topic qd mode in Kinetis Microcontrollers

qd mode

ralf1694 — Wed, 20 Jan 2016 14:19:35 GMT

Can not get qd mode to work.

Re: Cannot get quadrature decoder to work on K21FN1M0VMD12 FTM2

xiangjun_rong — Thu, 21 Jan 2016 03:14:23 GMT

Hi, Ralf,

I suppose that your code is correct. From hardware perspective, I suppose you connect the encoder signals PhaseA/PhaseB with 90 degree phase shift to the PTA10(FTM2_QD_PHA) and PTA11(FTM2_QD_PHB), then rotate the motor shaft manually so that the Encoder sensor can generate the PhaseA and PhaseB edges and FTM can count the edges. If the motor shaft is still, no edges of PhaseA and PhaseB signal are generated, the FTM counter will be zero.

Regarding your code, I suppose you have enable the POPTA gate clock in the SIM_SCGC5 by the code such as SIM_SCGC5|=0x200; prior to your code: PORTA_PCR10 = PORT_PCR_MUX(6);

Regarding the test, pls check the FTM2_CNT register directly in the debugger of the tools and check it's value.

Hope it can help you

Xiangjun rong

Re: Cannot get quadrature decoder to work on K21FN1M0VMD12 FTM2

ralf1694 — Thu, 21 Jan 2016 08:39:24 GMT

Hi Xiangjun,

I enable the PORTA gate clock before muxing the port. I spin the motor but the FTM2_CNT (debug) register is always null.

Re: Cannot get quadrature decoder to work on K21FN1M0VMD12 FTM2

xiangjun_rong — Thu, 21 Jan 2016 09:25:21 GMT

Hi, ralf,

Pls set the FTMEN bit by the code:FTM2_MODE|=0x05; //enable FTM2 module. I do not suggest you use center-alignment, but I do not think it is the cause of the issue either.

Pls have a try. If you still have problem, I will test on my tower board tomorrow.

Xiangjun Rong

Re: Cannot get quadrature decoder to work on K21FN1M0VMD12 FTM2

ralf1694 — Thu, 21 Jan 2016 13:03:27 GMT

hi xiangjun.

i solved the problem. the pha and phb signal goes throw a mux and the mux input was wrong.

thank you for your fast answers!